Processes for synthesizing unsymmetrical disiloxanes

Abstract

Described herein are methods for making alkenyl disiloxanes, comprising combining an alkenyl halosilane with an alkyl halosilane and adding the mixture to water, an acidic aqueous solution, or a basic aqueous solution. The ratio of the alkenyl halosilane to the alkyl halosilane is about 10:1 to about 1:10. The alkenyl halosilane and the alkyl halosilane are mixed at about 20° C. to about 45° C. The reaction product is separated and washed with saturated alkali carbonate solution.

The invention claimed is: 
     
         1 . A process for making alkenyl disiloxanes, comprising:
 combining an alkenyl halosilane with an alkyl halosilane and adding the mixture to water, an acidic aqueous solution, or a basic aqueous solution, wherein:   the alkenyl halosilane has Formula A   
       
         
           
           
               
               
           
         
       
       and
 the alkyl halosilane has Formula B 
 
       
         
           
           
               
               
           
         
       
       wherein:
 X is, independently at each occurrence, F, Cl, Br or I; 
 n is 0, 1, 2, 3, 4, 5, or 6; 
 R 1  is, independently at each occurrence, H or C1-C3 alkyl; 
 R 2  is, independently at each occurrence, H or C1-C3 alkyl; 
 also provided that one or more of R 1  and one or more of R 2  can combine to form a ring; 
 R 3  is, independently at each occurrence, H or C1-C6 alkyl; 
 one R 4  is H; and 
 each remaining R 4  are C1-C3 alkyl at each occurrence. 
 
     
     
         2 . The process of  claim 1 , wherein the ratio of the alkenyl halosilane to the alkyl halosilane is about 1:5 to about 1:0.5. 
     
     
         3 . The process of  claim 1 , wherein the alkenyl halosilane to the alkyl halosilane are mixed at about 20° C. to about 45° C. 
     
     
         4 . The process of  claim 1 , further comprising separating the reaction product to form an aqueous layer and a siloxane layer containing the alkenyl disiloxane, and washing the siloxane layer with a bicarbonate solution. 
     
     
         5 . The process of  claim 4 , further comprising drying the siloxane layer after washing. 
     
     
         6 . The process of  claim 1 , further comprising recovering the alkenyl disiloxane. 
     
     
         7 . The process of  claim 1 , wherein the alkenyl disiloxane is a compound of a Formula I: 
       
         
           
           
               
               
           
         
       
       wherein:
 n is 0, 1, 2, 3, 4, 5, or 6; 
 R 1  is, independently at each occurrence, H or C1-C3 alkyl; 
 R 2  is, independently at each occurrence, H or C1-C3 alkyl; 
 also provided that one or more of R 1  and one or more of R 2  can combine to form a ring; 
 R 3  is, independently at each occurrence, H or C1-C6 alkyl; 
 one R 4  is H; and 
 each remaining R 4  are C1-C3 alkyl at each occurrence. 
 
     
     
         8 . The process of  claim 1 , wherein the alkenyl disiloxane is 1-(hex-5-en-1-yl)-1,1,3,3-tetramethyldisiloxane, 5-norbornen-2-yl(ethyl)-1,1,3,3-tetramethyldisiloxane, or vinyltetramethyldisiloxane. 
     
     
         9 . The process of  claim 1 , wherein X is Cl and R 3  is methyl at both occurrences. 
     
     
         10 . The process of  claim 1 , wherein the compound of Formula A is 5-hexenyldimethylchlorosilane, 5-norbornen-2-yl(ethyl)chlorodimethylsilane, or dimethylvinylchlorosilane. 
     
     
         11 . The process of  claim 1 , wherein X is Cl and two of R 4  are methyl. 
     
     
         12 . The process of  claim 1 , wherein the compound of Formula B is dimethylchlorosilane or trimethylchlorosilane. 
     
     
         13 . The process of  claim 4 , further comprising recovering the alkenyl disiloxane. 
     
     
         14 . The process of  claim 5 , further comprising recovering the alkenyl disiloxane. 
     
     
         15 . The process of  claim 1 , wherein one or more of R 1  and one or more of R 2  combine to form a ring. 
     
     
         16 . The process of  claim 15 , wherein the compound of Formula A is 5-norbornen-2-yl(ethyl)chlorodimethylsilane. 
     
     
         17 . The process of  claim 1 , wherein n is 3, 4, or 5. 
     
     
         18 . The process of  claim 7 , wherein one or more of R 1  and one or more of R 2  combine to form a 5 to 8-membered ring. 
     
     
         19 . The process of  claim 18 , wherein the ring comprises 5-norbornen-2-yl. 
     
     
         20 . The process of  claim 7 , wherein n is 3, 4, or 5.